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Diffstat (limited to 'wire_format_derive/wire_format_derive.rs')
| -rw-r--r-- | wire_format_derive/wire_format_derive.rs | 303 |
1 files changed, 0 insertions, 303 deletions
diff --git a/wire_format_derive/wire_format_derive.rs b/wire_format_derive/wire_format_derive.rs deleted file mode 100644 index 290ffc5..0000000 --- a/wire_format_derive/wire_format_derive.rs +++ /dev/null @@ -1,303 +0,0 @@ -// Copyright 2018 The Chromium OS Authors. All rights reserved. -// Use of this source code is governed by a BSD-style license that can be -// found in the LICENSE file. - -//! Derives a 9P wire format encoding for a struct by recursively calling -//! `WireFormat::encode` or `WireFormat::decode` on the fields of the struct. -//! This is only intended to be used from within the `p9` crate. - -#![recursion_limit = "256"] - -extern crate proc_macro; -extern crate proc_macro2; - -#[macro_use] -extern crate quote; - -#[macro_use] -extern crate syn; - -use proc_macro2::{Span, TokenStream}; -use syn::spanned::Spanned; -use syn::{Data, DeriveInput, Fields, Ident}; - -/// The function that derives the actual implementation. -#[proc_macro_derive(P9WireFormat)] -pub fn p9_wire_format(input: proc_macro::TokenStream) -> proc_macro::TokenStream { - let input = parse_macro_input!(input as DeriveInput); - p9_wire_format_inner(input).into() -} - -fn p9_wire_format_inner(input: DeriveInput) -> TokenStream { - if !input.generics.params.is_empty() { - return quote! { - compile_error!("derive(P9WireFormat) does not support generic parameters"); - }; - } - - let container = input.ident; - - let byte_size_impl = byte_size_sum(&input.data); - let encode_impl = encode_wire_format(&input.data); - let decode_impl = decode_wire_format(&input.data, &container); - - let scope = format!("wire_format_{}", container).to_lowercase(); - let scope = Ident::new(&scope, Span::call_site()); - quote! { - mod #scope { - extern crate std; - use self::std::io; - use self::std::result::Result::Ok; - - use super::#container; - - use protocol::WireFormat; - - impl WireFormat for #container { - fn byte_size(&self) -> u32 { - #byte_size_impl - } - - fn encode<W: io::Write>(&self, _writer: &mut W) -> io::Result<()> { - #encode_impl - } - - fn decode<R: io::Read>(_reader: &mut R) -> io::Result<Self> { - #decode_impl - } - } - } - } -} - -// Generate code that recursively calls byte_size on every field in the struct. -fn byte_size_sum(data: &Data) -> TokenStream { - if let Data::Struct(ref data) = *data { - if let Fields::Named(ref fields) = data.fields { - let fields = fields.named.iter().map(|f| { - let field = &f.ident; - let span = field.span(); - quote_spanned! {span=> - WireFormat::byte_size(&self.#field) - } - }); - - quote! { - 0 #(+ #fields)* - } - } else { - unimplemented!(); - } - } else { - unimplemented!(); - } -} - -// Generate code that recursively calls encode on every field in the struct. -fn encode_wire_format(data: &Data) -> TokenStream { - if let Data::Struct(ref data) = *data { - if let Fields::Named(ref fields) = data.fields { - let fields = fields.named.iter().map(|f| { - let field = &f.ident; - let span = field.span(); - quote_spanned! {span=> - WireFormat::encode(&self.#field, _writer)?; - } - }); - - quote! { - #(#fields)* - - Ok(()) - } - } else { - unimplemented!(); - } - } else { - unimplemented!(); - } -} - -// Generate code that recursively calls decode on every field in the struct. -fn decode_wire_format(data: &Data, container: &Ident) -> TokenStream { - if let Data::Struct(ref data) = *data { - if let Fields::Named(ref fields) = data.fields { - let values = fields.named.iter().map(|f| { - let field = &f.ident; - let span = field.span(); - quote_spanned! {span=> - let #field = WireFormat::decode(_reader)?; - } - }); - - let members = fields.named.iter().map(|f| { - let field = &f.ident; - quote! { - #field: #field, - } - }); - - quote! { - #(#values)* - - Ok(#container { - #(#members)* - }) - } - } else { - unimplemented!(); - } - } else { - unimplemented!(); - } -} - -#[cfg(test)] -mod tests { - use super::*; - - #[test] - fn byte_size() { - let input: DeriveInput = parse_quote! { - struct Item { - ident: u32, - with_underscores: String, - other: u8, - } - }; - - let expected = quote! { - 0 - + WireFormat::byte_size(&self.ident) - + WireFormat::byte_size(&self.with_underscores) - + WireFormat::byte_size(&self.other) - }; - - assert_eq!(byte_size_sum(&input.data).to_string(), expected.to_string()); - } - - #[test] - fn encode() { - let input: DeriveInput = parse_quote! { - struct Item { - ident: u32, - with_underscores: String, - other: u8, - } - }; - - let expected = quote! { - WireFormat::encode(&self.ident, _writer)?; - WireFormat::encode(&self.with_underscores, _writer)?; - WireFormat::encode(&self.other, _writer)?; - Ok(()) - }; - - assert_eq!( - encode_wire_format(&input.data).to_string(), - expected.to_string(), - ); - } - - #[test] - fn decode() { - let input: DeriveInput = parse_quote! { - struct Item { - ident: u32, - with_underscores: String, - other: u8, - } - }; - - let container = Ident::new("Item", Span::call_site()); - let expected = quote! { - let ident = WireFormat::decode(_reader)?; - let with_underscores = WireFormat::decode(_reader)?; - let other = WireFormat::decode(_reader)?; - Ok(Item { - ident: ident, - with_underscores: with_underscores, - other: other, - }) - }; - - assert_eq!( - decode_wire_format(&input.data, &container).to_string(), - expected.to_string(), - ); - } - - #[test] - fn end_to_end() { - let input: DeriveInput = parse_quote! { - struct Niijima_先輩 { - a: u8, - b: u16, - c: u32, - d: u64, - e: String, - f: Vec<String>, - g: Nested, - } - }; - - let expected = quote! { - mod wire_format_niijima_先輩 { - extern crate std; - use self::std::io; - use self::std::result::Result::Ok; - - use super::Niijima_先輩; - - use protocol::WireFormat; - - impl WireFormat for Niijima_先輩 { - fn byte_size(&self) -> u32 { - 0 - + WireFormat::byte_size(&self.a) - + WireFormat::byte_size(&self.b) - + WireFormat::byte_size(&self.c) - + WireFormat::byte_size(&self.d) - + WireFormat::byte_size(&self.e) - + WireFormat::byte_size(&self.f) - + WireFormat::byte_size(&self.g) - } - - fn encode<W: io::Write>(&self, _writer: &mut W) -> io::Result<()> { - WireFormat::encode(&self.a, _writer)?; - WireFormat::encode(&self.b, _writer)?; - WireFormat::encode(&self.c, _writer)?; - WireFormat::encode(&self.d, _writer)?; - WireFormat::encode(&self.e, _writer)?; - WireFormat::encode(&self.f, _writer)?; - WireFormat::encode(&self.g, _writer)?; - Ok(()) - } - fn decode<R: io::Read>(_reader: &mut R) -> io::Result<Self> { - let a = WireFormat::decode(_reader)?; - let b = WireFormat::decode(_reader)?; - let c = WireFormat::decode(_reader)?; - let d = WireFormat::decode(_reader)?; - let e = WireFormat::decode(_reader)?; - let f = WireFormat::decode(_reader)?; - let g = WireFormat::decode(_reader)?; - Ok(Niijima_先輩 { - a: a, - b: b, - c: c, - d: d, - e: e, - f: f, - g: g, - }) - } - } - } - }; - - assert_eq!( - p9_wire_format_inner(input).to_string(), - expected.to_string(), - ); - } -} |